Bacon, ham and sausages rank alongside cigarettes as a major cause of cancer, the World Health Organisation has said, placing cured and processed meats in the same category as asbestos, alcohol, arsenic and tobacco. The report from the WHO's International Agency for Research on Cancer said there was enough evidence to rank processed meats as group 1 carcinogens because of a causal link with bowel cancer. It places red meat in group 2A, as "probably carcinogenic to humans". Eating red meat is also linked to pancreatic and prostate cancer, the IARC says. The IARC's experts concluded that each 50-gram (1.8-ounce) portion of processed meat eaten daily increased the risk of colorectal cancer by 18%.

"For an individual, the risk of developing colorectal cancer because of their consumption of processed meat remains small, but this risk increases with the amount of meat consumed", said Dr Kurt Straif, head of the IARC monographs programme. "In view of the large number of people who consume processed meat, the global impact on cancer incidence is of public health importance."

The decision from the IARC, after a year of deliberations by international scientists, will be welcomed by cancer researchers but it triggered an immediate and furious response from the industry, and the scientists it funds, who rejected any comparison between cigarettes and meat.